SANAA, Dec. 3 (Xinhua) -- United Nations Envoy to Yemen Martin Griffiths arrived in the rebel-held capital Sanaa on Monday, in a brief stop to get Houthi delegates to Sweden.

Griffiths refused to talk to reporters upon his arrival and rushed to meet Houthi officials.

Griffiths office said the talks in Sweden would more likely start on Wednesday.

The Houthi delegation was set to depart along with the UN envoy shortly after the 50 wounded rebel fighters boarded another UN plane for further treatment in Oman.

However, the injured have been waiting at the airport for more than six hours as their plane has not yet arrived.

Spokesman of the coalition forces Turki al-Maliki said in a press conference in Riyadh that the move came upon a "request of the UN envoy Griffiths to facilitate the evacuation of injured to Muscat for humanitarian reasons."

"The facilitation comes within the confidence-building framework between the Yemeni parties to prepare for the upcoming peace talks in Sweden," al-Maliki said.

The blocking of Houthi injured fighters from getting further medical treatment was a key reason behind the collapse of previous round of talks in Geneva in September.

Monday's apparent breakthrough would pave the way for fresh negotiations in Sweden in next few days.

Meanwhile, Houthi negotiating delegates said they have received guarantees from the United Nations for a safe depart and return to Sanaa, but insist the group's injured should be evacuated first.

On Nov. 13, the British Foreign Office said its foreign secretary Jeremy Hunt has given an "upbeat assessment" of the chances of political talks and a cease-fire in the four-year Yemen civil war after his visit to Riyadh, ended with Saudi Arabia agreeing to allow the evacuation of some wounded Houthi fighters.

Saudi Arabia is leading the Arab military coalition that intervened in Yemen in March 2015 to support the government of President Abd-Rabbu Mansour Hadi after the Houthi rebels forced him into exile.